1. Field of the Invention
The present invention relates to a plasma display panel (PDP) and the method for making the same, and more particularly, to a PDP having two plates tightly fixed together and the method for making the same.
2. Description of the Prior Art
With the continuing advances of the electronics industry, the consumer""s demand for flat panel displays (FPD) has increased, with plasma display panels (PDP) having some of the greatest market potential of all FPDs. Typically, a front plate and a rear plate of a PDP are formed first, and the front plate is inverted for mounting onto the rear plate. The two plates are then sealed together to form closed discharge cells. The tightness of the sealing process can affect the yield of subsequent processes that remove gases from, or inject gases into, the PDP. Additionally, the sealing process may affect the isolation between each discharge cell. Hence, a method for tightly sealing the front plate and the rear plate is necessary.
Please refer to FIG. 1. FIG. 1 is a perspective view of a method for sealing a front plate 12 and a rear plate 14 of a PDP 10 according to the prior art. The prior art PDP 10 includes the front plate 12, the rear plate 14 in parallel with the front plate 12, and a plurality of barrier ribs 16 on a predetermined area of the rear plate 14.
In the prior art method for sealing the two plates, a sealing layer 18 is formed and surrounds the barrier ribs 16 on the rear plate 14, and a corresponding sealing layer 20 is also formed on the front plate 12. The front plate 12 and the rear plate 14 are affixed, and the sealing layer 18 and the sealing layer 20 temporarily bond to each other. The front plate 12 and the rear plate 14 are then placed into an oven and heated to 450xc2x0 C. (842xc2x0 F.), the frit within the sealing layers 18 and 20 are melted. After cooling, the front plate 12 and the rear plate 14 are tightly fixed together.
The PDP 10 is frequently used for displays with a large area. As the scale of the PDP increases, relying only on the sealing layers 18 and 20 is not sufficient to ensure a tight seal between the front plate 12 and the rear plate 14. This is especially true as it is not easy to align the sealing layers 18 and 20 when using the prior art method. Furthermore, the barrier ribs 16 are not all of the same height, which may allow some space between the front plate 12 and the top end of any barrier rib 16 that has a low height. This results in cross talk between two discharge cells, and reduces the isolation properties of the barrier ribs 16. However, if the width of the barrier rib 16 is increased to prevent cross talk, the number of the discharge cells must necessarily decrease due to limited size of the plates 12 and 14, preventing the construction of a high resolution PDP.
It is therefore a primary objective of the present invention to provide a PDP that has a front plate tightly fixed to the rear plate with a precise alignment so as to solve the above mentioned problems.
In a preferred embodiment of the present invention, the PDP includes a rear plate, a plurality of barrier ribs on the rear plate, and a front plate in parallel with the rear plate. The front plate includes a transparent dielectric layer, a plurality of joint notches on the transparent dielectric layer, and a protective layer on the transparent dielectric layer that covers the joint notches. The position of each of the joint notches is aligned with the position of a corresponding barrier rib, and each joint notch has a filler that is used to fix the joint notch and the corresponding barrier rib. When the front plate is mounted onto the rear plate, the top end of each of the barrier ribs of the rear plate is pushed through the protective layer above the corresponding joint notch on the transparent dielectric layer and is embedded in the corresponding joint notch of the front plate. The filler in each of the joint notches fills the gap between the top end of the barrier rib embedded in the joint notch and the joint notch so that the front plate is tightly fixed to the rear plate.
It is an advantage of the present invention that each of the barrier ribs is embedded in a corresponding joint notch. the fillers are used to seal the two plates together tightly, greatly increasing the sealing strength of the present invention PDP, and ensuring that there are no gaps between the top ends of the barrier ribs and their joint notches. Furthermore, the front plate and the rear plate can be easily aligned.